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de Souza Rocha B, Silva JSD, Pedreira JGB, Montagnoli TL, Barreiro EJ, Zapata-Sudo G. Antihypertensive Effect of New Agonist of Adenosine Receptor in Spontaneously Hypertensive Rats. Arq Bras Cardiol 2024; 121:e20230405. [PMID: 38597541 DOI: 10.36660/abc.20230405] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2023] [Accepted: 11/14/2023] [Indexed: 04/11/2024] Open
Abstract
BACKGROUND Systemic arterial hypertension is a risk factor for cardiac, renal, and metabolic dysfunction. The search for new strategies to prevent and treat cardiovascular diseases led to the synthesis of new N-acylhydrazones to produce antihypertensive effect. Adenosine receptors are an alternative target to reduce blood pressure because of their vasodilatory action and antioxidant properties, which may reduce oxidative stress characteristic of systemic arterial hypertension. OBJECTIVE To evaluate the antihypertensive profile of novel selenium-containing compounds designed to improve their interaction with adenosine receptors. METHODS Vascular reactivity was evaluated by recording the isometric tension of pre-contracted thoracic aorta of male Wistar rats after exposure to increasing concentrations of each derivative (0.1 to 100 μM). To investigate the antihypertensive effect in spontaneously hypertensive rats, systolic, diastolic, and mean arterial pressure and heart rate were determined after intravenous administration of 10 and 30 μmol/kg of the selected compound LASSBio-2062. RESULTS Compounds named LASSBio-2062, LASSBio-2063, LASSBio-2075, LASSBio-2076, LASSBio-2084, LASSBio-430, LASSBio-2092, and LASSBio-2093 promoted vasodilation with mean effective concentrations of 15.5 ± 6.5; 14.6 ± 2.9; 18.7 ± 9.6; 6.7 ± 4.1; > 100; 6.0 ± 3.6; 37.8 ± 11.8; and 15.9 ± 5.7 μM, respectively. LASSBio-2062 (30 μmol/kg) reduced mean arterial pressure in spontaneously hypertensive rats from 124.6 ± 8.6 to 72.0 ± 12.3 mmHg (p < 0.05). Activation of adenosine receptor subtype A3 and potassium channels seem to be involved in the antihypertensive effect of LASSBio-2062. CONCLUSIONS The new agonist of adenosine receptor and activator of potassium channels is a potential therapeutic agent to treat systemic arterial hypertension.
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Fisher CL, Pavan M, Salmaso V, Keyes RF, Wan TC, Pradhan B, Gao ZG, Smith BC, Jacobson KA, Auchampach JA. Extrahelical Binding Site for a 1 H-Imidazo[4,5-c]quinolin-4-amine A 3 Adenosine Receptor Positive Allosteric Modulator on Helix 8 and Distal Portions of Transmembrane Domains 1 and 7. Mol Pharmacol 2024; 105:213-223. [PMID: 38182432 PMCID: PMC10877738 DOI: 10.1124/molpharm.123.000784] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2023] [Revised: 11/27/2023] [Accepted: 12/12/2023] [Indexed: 01/07/2024] Open
Abstract
This study describes the localization and computational prediction of a binding site for the A3 adenosine receptor (A3AR) positive allosteric modulator 2-cyclohexyl-1H-imidazo[4,5-c]quinolin-4-(3,4-dichlorophenyl)amine (LUF6000). The work reveals an extrahelical lipid-facing binding pocket disparate from the orthosteric binding site that encompasses transmembrane domain (TMD) 1, TMD7, and Helix (H) 8, which was predicted by molecular modeling and validated by mutagenesis. According to the model, the nearly planar 1H-imidazo[4,5-c]quinolinamine ring system lies parallel to the transmembrane segments, inserted into an aromatic cage formed by π-π stacking interactions with the side chains of Y2847.55 in TMD7 and Y2938.54 in H8 and by π-NH bonding between Y2847.55 and the exocyclic amine. The 2-cyclohexyl group is positioned "upward" within a small hydrophobic subpocket created by residues in TMDs 1 and 7, while the 3,4-dichlorophenyl group extends toward the lipid interface. An H-bond between the N-1 amine of the heterocycle and the carbonyl of G291.49 further stabilizes the interaction. Molecular dynamics simulations predicted two metastable intermediates, one resembling a pose determined by molecular docking and a second involving transient interactions with Y2938.54; in simulations, each of these intermediates converges into the final bound state. Structure-activity-relationships for replacement of either of the identified exocyclic or endocyclic amines with heteroatoms lacking H-bond donating ability were consistent with the hypothetical pose. Thus, we characterized an allosteric pocket for 1H-imidazo[4,5-c]quinolin-4-amines that is consistent with data generated by orthogonal methods, which will aid in the rational design of improved A3AR positive allosteric modulators. SIGNIFICANCE STATEMENT: Orthosteric A3AR agonists have advanced in clinical trials for inflammatory conditions, liver diseases, and cancer. Thus, the clinical appeal of selective receptor activation could extend to allosteric enhancers, which would induce site- and time-specific activation in the affected tissue. By identifying the allosteric site for known positive allosteric modulators, structure-based drug discovery modalities can be enabled to enhance the pharmacological properties of the 1H-imidazo[4,5-c]quinolin-4-amine class of A3AR positive allosteric modulators.
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Affiliation(s)
- Courtney L Fisher
- Departments of Pharmacology & Toxicology and the Cardiovascular Center (C.L.F., T.C.W., J.A.A.) and Biochemistry and the Program in Chemical Biology (R.F.K., B.C.S.), Medical College of Wisconsin, Milwaukee, Wisconsin; Molecular Recognition Section, Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland (M.P., V.S., B.P., Z.-G.G., K.A.J.); and Department of Pharmaceutical and Pharmacological Sciences, University of Padua, Padua, Italy (V.S.)
| | - Matteo Pavan
- Departments of Pharmacology & Toxicology and the Cardiovascular Center (C.L.F., T.C.W., J.A.A.) and Biochemistry and the Program in Chemical Biology (R.F.K., B.C.S.), Medical College of Wisconsin, Milwaukee, Wisconsin; Molecular Recognition Section, Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland (M.P., V.S., B.P., Z.-G.G., K.A.J.); and Department of Pharmaceutical and Pharmacological Sciences, University of Padua, Padua, Italy (V.S.)
| | - Veronica Salmaso
- Departments of Pharmacology & Toxicology and the Cardiovascular Center (C.L.F., T.C.W., J.A.A.) and Biochemistry and the Program in Chemical Biology (R.F.K., B.C.S.), Medical College of Wisconsin, Milwaukee, Wisconsin; Molecular Recognition Section, Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland (M.P., V.S., B.P., Z.-G.G., K.A.J.); and Department of Pharmaceutical and Pharmacological Sciences, University of Padua, Padua, Italy (V.S.)
| | - Robert F Keyes
- Departments of Pharmacology & Toxicology and the Cardiovascular Center (C.L.F., T.C.W., J.A.A.) and Biochemistry and the Program in Chemical Biology (R.F.K., B.C.S.), Medical College of Wisconsin, Milwaukee, Wisconsin; Molecular Recognition Section, Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland (M.P., V.S., B.P., Z.-G.G., K.A.J.); and Department of Pharmaceutical and Pharmacological Sciences, University of Padua, Padua, Italy (V.S.)
| | - Tina C Wan
- Departments of Pharmacology & Toxicology and the Cardiovascular Center (C.L.F., T.C.W., J.A.A.) and Biochemistry and the Program in Chemical Biology (R.F.K., B.C.S.), Medical College of Wisconsin, Milwaukee, Wisconsin; Molecular Recognition Section, Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland (M.P., V.S., B.P., Z.-G.G., K.A.J.); and Department of Pharmaceutical and Pharmacological Sciences, University of Padua, Padua, Italy (V.S.)
| | - Balaram Pradhan
- Departments of Pharmacology & Toxicology and the Cardiovascular Center (C.L.F., T.C.W., J.A.A.) and Biochemistry and the Program in Chemical Biology (R.F.K., B.C.S.), Medical College of Wisconsin, Milwaukee, Wisconsin; Molecular Recognition Section, Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland (M.P., V.S., B.P., Z.-G.G., K.A.J.); and Department of Pharmaceutical and Pharmacological Sciences, University of Padua, Padua, Italy (V.S.)
| | - Zhan-Guo Gao
- Departments of Pharmacology & Toxicology and the Cardiovascular Center (C.L.F., T.C.W., J.A.A.) and Biochemistry and the Program in Chemical Biology (R.F.K., B.C.S.), Medical College of Wisconsin, Milwaukee, Wisconsin; Molecular Recognition Section, Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland (M.P., V.S., B.P., Z.-G.G., K.A.J.); and Department of Pharmaceutical and Pharmacological Sciences, University of Padua, Padua, Italy (V.S.)
| | - Brian C Smith
- Departments of Pharmacology & Toxicology and the Cardiovascular Center (C.L.F., T.C.W., J.A.A.) and Biochemistry and the Program in Chemical Biology (R.F.K., B.C.S.), Medical College of Wisconsin, Milwaukee, Wisconsin; Molecular Recognition Section, Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland (M.P., V.S., B.P., Z.-G.G., K.A.J.); and Department of Pharmaceutical and Pharmacological Sciences, University of Padua, Padua, Italy (V.S.)
| | - Kenneth A Jacobson
- Departments of Pharmacology & Toxicology and the Cardiovascular Center (C.L.F., T.C.W., J.A.A.) and Biochemistry and the Program in Chemical Biology (R.F.K., B.C.S.), Medical College of Wisconsin, Milwaukee, Wisconsin; Molecular Recognition Section, Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland (M.P., V.S., B.P., Z.-G.G., K.A.J.); and Department of Pharmaceutical and Pharmacological Sciences, University of Padua, Padua, Italy (V.S.)
| | - John A Auchampach
- Departments of Pharmacology & Toxicology and the Cardiovascular Center (C.L.F., T.C.W., J.A.A.) and Biochemistry and the Program in Chemical Biology (R.F.K., B.C.S.), Medical College of Wisconsin, Milwaukee, Wisconsin; Molecular Recognition Section, Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland (M.P., V.S., B.P., Z.-G.G., K.A.J.); and Department of Pharmaceutical and Pharmacological Sciences, University of Padua, Padua, Italy (V.S.)
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Tosh D, Fisher CL, Salmaso V, Wan TC, Campbell RG, Chen E, Gao ZG, Auchampach JA, Jacobson KA. First Potent Macrocyclic A 3 Adenosine Receptor Agonists Reveal G-Protein and β-Arrestin2 Signaling Preferences. ACS Pharmacol Transl Sci 2023; 6:1288-1305. [PMID: 37705595 PMCID: PMC10496144 DOI: 10.1021/acsptsci.3c00126] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2023] [Indexed: 09/15/2023]
Abstract
(N)-Methanocarba adenosine derivatives (A3 adenosine receptor (AR) agonists containing bicyclo[3.1.0]hexane replacing furanose) were chain-extended at N6 and C2 positions with terminal alkenes for ring closure. The resulting macrocycles of 17-20 atoms retained affinity, indicating a spatially proximal orientation of these receptor-bound chains, consistent with molecular modeling of 12. C2-Arylethynyl-linked macrocycle 19 was more A3AR-selective than 2-ether-linked macrocycle 12 (both 5'-methylamides, human (h) A3AR affinities (Ki): 22.1 and 25.8 nM, respectively), with lower mouse A3AR affinities. Functional hA3AR comparison of two sets of open/closed analogues in β-arrestin2 and Gi/o protein assays showed certain signaling preferences divergent from reference agonist Cl-IB-MECA 1. The potencies of 1 at all three Gαi isoforms were slightly less than its hA3AR binding affinity (Ki: 1.4 nM), while the Gαi1 and Gαi2 potencies of macrocycle 12 were roughly an order of magnitude higher than its radioligand binding affinity. Gαi2-coupling was enhanced in macrocycle 12 (EC50 2.56 nM, ∼40% greater maximal efficacy than 1). Di-O-allyl precursor 18 cyclized to form 19, increasing the Gαi1 potency by 7.5-fold. The macrocycles 12 and 19 and their open precursors 11 and 18 potently stimulated β-arrestin2 recruitment, with EC50 values (nM) of 5.17, 4.36, 1.30, and 4.35, respectively, and with nearly 50% greater efficacy compared to 1. This example of macrocyclization altering the coupling pathways of small-molecule (nonpeptide) GPCR agonists is the first for potent and selective macrocyclic AR agonists. These initial macrocyclic derivatives can serve as a guide for the future design of macrocyclic AR agonists displaying unanticipated pharmacology.
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Affiliation(s)
- Dilip
K. Tosh
- Laboratory
of Bioorganic Chemistry, National Institute of Diabetes and Digestive
and Kidney Disease, National Institutes
of Health, 9000 Rockville
Pike, Bethesda, Maryland 20892, United States
| | - Courtney L. Fisher
- Department
of Pharmacology & Toxicology and the Cardiovascular Center, Medical College of Wisconsin, 8701 Watertown Plank Road, Milwaukee, Wisconsin 53226, United States
| | - Veronica Salmaso
- Laboratory
of Bioorganic Chemistry, National Institute of Diabetes and Digestive
and Kidney Disease, National Institutes
of Health, 9000 Rockville
Pike, Bethesda, Maryland 20892, United States
- Molecular
Modeling Section, Department of Pharmaceutical and Pharmacological
Sciences, University of Padua, Padua 35131, Italy
| | - Tina C. Wan
- Department
of Pharmacology & Toxicology and the Cardiovascular Center, Medical College of Wisconsin, 8701 Watertown Plank Road, Milwaukee, Wisconsin 53226, United States
| | - Ryan G. Campbell
- Laboratory
of Bioorganic Chemistry, National Institute of Diabetes and Digestive
and Kidney Disease, National Institutes
of Health, 9000 Rockville
Pike, Bethesda, Maryland 20892, United States
| | - Eric Chen
- Laboratory
of Bioorganic Chemistry, National Institute of Diabetes and Digestive
and Kidney Disease, National Institutes
of Health, 9000 Rockville
Pike, Bethesda, Maryland 20892, United States
| | - Zhan-Guo Gao
- Laboratory
of Bioorganic Chemistry, National Institute of Diabetes and Digestive
and Kidney Disease, National Institutes
of Health, 9000 Rockville
Pike, Bethesda, Maryland 20892, United States
| | - John A. Auchampach
- Department
of Pharmacology & Toxicology and the Cardiovascular Center, Medical College of Wisconsin, 8701 Watertown Plank Road, Milwaukee, Wisconsin 53226, United States
| | - Kenneth A. Jacobson
- Laboratory
of Bioorganic Chemistry, National Institute of Diabetes and Digestive
and Kidney Disease, National Institutes
of Health, 9000 Rockville
Pike, Bethesda, Maryland 20892, United States
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4
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Gao ZG, Auchampach JA, Jacobson KA. Species dependence of A 3 adenosine receptor pharmacology and function. Purinergic Signal 2023; 19:523-550. [PMID: 36538251 PMCID: PMC9763816 DOI: 10.1007/s11302-022-09910-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2022] [Accepted: 11/26/2022] [Indexed: 12/24/2022] Open
Abstract
Efforts to fully understand pharmacological differences between G protein-coupled receptor (GPCR) species homologues are generally not pursued in detail during the drug development process. To date, many GPCRs that have been successfully targeted are relatively well-conserved across species in amino acid sequence and display minimal variability of biological effects. However, the A3 adenosine receptor (AR), an exciting drug target for a multitude of diseases associated with tissue injury, ischemia, and inflammation, displays as little as 70% sequence identity among mammalian species (e.g., rodent vs. primate) commonly used in drug development. Consequently, the pharmacological properties of synthetic A3AR ligands vary widely, not only in binding affinity, selectivity, and signaling efficacy, but to the extent that some function as agonists in some species and antagonists in others. Numerous heterocyclic antagonists that have nM affinity at the human A3AR are inactive or weakly active at the rat and mouse A3ARs. Positive allosteric modulators, including the imidazo [4,5-c]quinolin-4-amine derivative LUF6000, are only active at human and some larger animal species that have been evaluated (rabbit and dog), but not rodents. A3AR agonists evoke systemic degranulation of rodent, but not human mast cells. The rat A3AR undergoes desensitization faster than the human A3AR, but the human homologue can be completely re-sensitized and recycled back to the cell surface. Thus, comprehensive pharmacological evaluation and awareness of potential A3AR species differences are critical in studies to further understand the basic biological functions of this unique AR subtype. Recombinant A3ARs from eight different species have been pharmacologically characterized thus far. In this review, we describe in detail current knowledge of species differences in genetic identity, G protein-coupling, receptor regulation, and both orthosteric and allosteric A3AR pharmacology.
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Affiliation(s)
- Zhan-Guo Gao
- Molecular Recognition Section, Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD, 20892-0810, USA.
| | - John A Auchampach
- Department of Pharmacology and Toxicology, and the Cardiovascular Center, Medical College of Wisconsin, 8701 Watertown Plank Road, Milwaukee, WI, 53226, USA
| | - Kenneth A Jacobson
- Molecular Recognition Section, Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD, 20892-0810, USA.
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Khanal S, Bok E, Kim J, Park GH, Choi DY. Dopaminergic neuroprotective effects of inosine in MPTP-induced parkinsonian mice via brain-derived neurotrophic factor upregulation. Neuropharmacology 2023:109652. [PMID: 37422180 DOI: 10.1016/j.neuropharm.2023.109652] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2023] [Revised: 07/03/2023] [Accepted: 07/04/2023] [Indexed: 07/10/2023]
Abstract
Parkinson's disease (PD) is the second most common neurodegenerative disease. However, no curative or modifying therapy is known. Inosine is a purine nucleoside that increases brain-derived neurotrophic factor (BDNF) expression in the brain through adenosine receptors. Herein, we investigated the neuroprotective effects of inosine and elucidated the mechanisms underlying its pharmacological action. Inosine rescued SH-SY5Y neuroblastoma cells from MPP+ injury in a dose-dependent manner. Inosine protection correlated with BDNF expression and the activation of its downstream signaling cascade, as the TrkB receptor inhibitor, K252a and siRNA against the BDNF gene remarkably reduced the protective effects of inosine. Blocking the A1 or A2A adenosine receptors diminished BDNF induction and the rescuing effect of inosine, indicating a critical role of adenosine A1 and A2A receptors in inosine-related BDNF elevation. We assessed whether the compound could protect dopaminergic neurons from MPTP-induced neuronal injury. Beam-walking and challenge beam tests revealed that inosine pretreatment for 3 weeks reduced the MPTP-induced motor function impairment. Inosine ameliorated dopaminergic neuronal loss and MPTP-mediated astrocytic and microglial activation in the substantia nigra and striatum. Inosine ameliorated the depletion of striatal dopamine and its metabolite following MPTP injection. BDNF upregulation and the activation of its downstream signaling pathway seemingly correlate with the neuroprotective effects of inosine. To our knowledge, this is the first study to demonstrate the neuroprotective effects of inosine against MPTP neurotoxicity via BDNF upregulation. These findings highlight the therapeutic potential of inosine in dopaminergic neurodegeneration in PD brains.
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Affiliation(s)
- Shristi Khanal
- College of Pharmacy, Yeungnam University, 280 Daehakro, Gyeongsan, Gyeongbuk, 38541, Republic of Korea.
| | - Eugene Bok
- Dementia Research Group, Korea Brain Research Institute, Daegu, 41062, Republic of Korea.
| | - Jaekwang Kim
- Dementia Research Group, Korea Brain Research Institute, Daegu, 41062, Republic of Korea.
| | - Gyu Hwan Park
- College of Pharmacy, Kyungpook National University, Daegu, 41566, Republic of Korea.
| | - Dong-Young Choi
- College of Pharmacy, Yeungnam University, 280 Daehakro, Gyeongsan, Gyeongbuk, 38541, Republic of Korea.
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Jacobson KA, Pradhan B, Wen Z, Pramanik A. New paradigms in purinergic receptor ligand discovery. Neuropharmacology 2023; 230:109503. [PMID: 36921890 PMCID: PMC10233512 DOI: 10.1016/j.neuropharm.2023.109503] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2023] [Revised: 02/28/2023] [Accepted: 03/11/2023] [Indexed: 03/14/2023]
Abstract
The discovery and clinical implementation of modulators of adenosine, P2Y and P2X receptors (comprising nineteen subtypes) have progressed dramatically in ∼50 years since Burnstock's definition of purinergic signaling. Although most clinical trials of selective ligands (agonists and antagonists) of certain purinergic receptors failed, there is a renewed impetus to redirect efforts to new disease conditions and the discovery of more selective or targeted compounds with potentially reduced side effects, such as biased GPCR agonists. The elucidation of new receptor and enzyme structures is steering rational design of potent and selective agonists, antagonists, allosteric modulators and inhibitors. A2A adenosine receptor (AR) antagonists are being applied to neurodegenerative conditions and cancer immunotherapy. A3AR agonists have potential for treating chronic inflammation (e.g. psoriasis), stroke and pain, as well as cancer. P2YR modulators are being considered for treating inflammation, metabolic disorders, acute kidney injury, cancer, pain and other conditions, often with an immune mechanism. ADP-activated P2Y12R antagonists are widely used as antithrombotic drugs, while their repurposing toward neuroinflammation is considered. P2X3 antagonists have been in clinical trials for chronic cough. P2X7 antagonists have been in clinical trials for inflammatory diseases and depression (compounds that penetrate the blood-brain barrier). Thus, purinergic signaling is now recognized as an immense regulatory system in the body for rebalancing tissues and organs under stress, which can be adjusted by drug intervention for therapeutic purposes. The lack of success of many previous clinical trials can be overcome given more advanced pharmacokinetic and pharmacodynamic approaches, including structure-based drug design, prodrugs and biased signaling. This article is part of the Special Issue on "Purinergic Signaling: 50 years".
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Affiliation(s)
- Kenneth A Jacobson
- Molecular Recognition Section, Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, 9000 Rockville Pike, Bethesda, MD, 20892, USA.
| | - Balaram Pradhan
- Molecular Recognition Section, Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, 9000 Rockville Pike, Bethesda, MD, 20892, USA.
| | - Zhiwei Wen
- Molecular Recognition Section, Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, 9000 Rockville Pike, Bethesda, MD, 20892, USA.
| | - Asmita Pramanik
- Molecular Recognition Section, Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, 9000 Rockville Pike, Bethesda, MD, 20892, USA.
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7
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Fallot LB, Suresh RR, Fisher CL, Salmaso V, O'Connor RD, Kaufman N, Gao ZG, Auchampach JA, Jacobson KA. Structure-Activity Studies of 1 H-Imidazo[4,5- c]quinolin-4-amine Derivatives as A 3 Adenosine Receptor Positive Allosteric Modulators. J Med Chem 2022; 65:15238-15262. [PMID: 36367749 PMCID: PMC10354740 DOI: 10.1021/acs.jmedchem.2c01170] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
We previously reported 1H-imidazo[4,5-c]quinolin-4-amines as A3 adenosine receptor (A3AR) positive allosteric modulators (PAMs). A3AR agonists, but not PAMs, are in clinical trials for inflammatory diseases and liver conditions. We synthesized new analogues to distinguish 2-cyclopropyl antagonist 17 (orthosteric interaction demonstrated by binding and predicted computationally) from PAMs (derivatives with large 2-alkyl/cycloalkyl/bicycloalkyl groups). We predicted PAM binding at a hydrophobic site on the A3AR cytosolic interface. Although having low Caco-2 permeability and high plasma protein binding, hydrophobic 2-cyclohept-4-enyl-N-3,4-dichlorophenyl, MRS7788 18, and 2-heptan-4-yl-N-4-iodophenyl, MRS8054 39, derivatives were orally bioavailable in rat. 2-Heptan-4-yl-N-3,4-dichlorophenyl 14 and 2-cyclononyl-N-3,4-dichlorophenyl 20 derivatives and 39 greatly enhanced Cl-IB-MECA-stimulated [35S]GTPγS binding Emax, with only 12b trending toward decreasing the agonist EC50. A feasible route for radio-iodination at the p-position of a 4-phenylamino substituent suggests a potential radioligand for allosteric site binding. Herein, we advanced an allosteric approach to developing A3AR-activating drugs that are potentially event- and site-specific in action.
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Affiliation(s)
- Lucas B Fallot
- Molecular Recognition Section, Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, 9000 Rockville Pike, Bethesda, Maryland 20892, United States
- Department of Biochemistry and Molecular Biology, Uniformed Services University of the Health Sciences, 4301 Jones Bridge Road, Bethesda, Maryland 20814, United States
- Department of Chemistry and Life Science, United States Military Academy, 646 Swift Road, West Point, New York 10996, United States
| | - R Rama Suresh
- Molecular Recognition Section, Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, 9000 Rockville Pike, Bethesda, Maryland 20892, United States
| | | | - Veronica Salmaso
- Molecular Recognition Section, Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, 9000 Rockville Pike, Bethesda, Maryland 20892, United States
| | - Robert D O'Connor
- Molecular Recognition Section, Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, 9000 Rockville Pike, Bethesda, Maryland 20892, United States
| | - Noy Kaufman
- Molecular Recognition Section, Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, 9000 Rockville Pike, Bethesda, Maryland 20892, United States
| | - Zhan-Guo Gao
- Molecular Recognition Section, Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, 9000 Rockville Pike, Bethesda, Maryland 20892, United States
| | | | - Kenneth A Jacobson
- Molecular Recognition Section, Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, 9000 Rockville Pike, Bethesda, Maryland 20892, United States
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